A conventional hydroelectric installation, whether operated as a pump or as a generator, has an electric machine connected vertically above a single-stage hydraulic machine through a shaft connecting the electric rotor to the hydraulic runner. In the conventional installation procedure, a pit is dug and a draft conduit, to take output water, is formed through the bottom to the pit. The up-turned pipe of the draft conduit, surrounded by concrete, is used as a basis on which the hydraulic machine is assembled by arranging the spiral casing, speed ring and lower cover thereof on top. The runner is placed in the lower cover and the upper cover fitted. An operating drive and drive linkage for the guide vanes of the water chamber are positioned above the upper cover, connected to the guide vanes. This hydraulic assembly is concreted in place. The electric machine is then installed above the hydraulic machine, the main rotor shaft of the electric machine being passed from above through the upper cover and connected to the runner of the hydraulic machine.
In the prior art, JP-A-56/83572 describes a hydroelectric generator of the type mentioned.
The installation of such a hydroelectric machine is a very long and arduous task. The present inventors have reconsidered the installation procedure and developed a new installation concept which can produce a number of useful advantages.